Restructuring - Reconciliation of Beginning and Ending Liability Balances by Expense Type (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Restructuring costs and Reserve [Line Items]
Costs charged to expense	$ 985
Severance Expense [Member]
Restructuring costs and Reserve [Line Items]
Costs charged to expense	954
Costs paid or otherwise settled	954
Other Expenses [Member]
Restructuring costs and Reserve [Line Items]
Costs charged to expense	31
Costs paid or otherwise settled	29
Ending Balance	$ 2